I've been discussing this topic (vegan diet & Crossfit) with one of our gym members who has been vegan for a number of years, and gives 100% in her workouts, but has been having difficulty gaining strength. I'm not certain how long she's been Crossfiting, but I'm thinking around a year or two. My original thought was that strength and muscle gain would be more difficult on a vegan diet, but anecdotally at least, it seems there are a number of Crossfitters that have had success while eating vegan. I understand there are many variables beyond just diet (i.e. genetics, activity level prior to Crossfit, specific foods consumed, etc), but I'd like to get some general feedback from those who are vegan and do Crossfit.

Have you found it difficult to gain strength and muscle mass? What supplements do you take, if any? I believe only animal products naturally contain B12 and Creatine - do you supplement these? If you were active before and after going vegan, did you experience any significant changes in fitness level; energy level? Did you lose weight? Have you felt being vegan has affected your Crossfit performance positively or negatively?

I get a lot of this is subjective - that's what I'm looking for.

I did read other threads throughout the board, as well as various other sources (example links below), but would still like more feedback to flesh out this topic.